Refrigerating apparatus



Nov. 5, 1940.

R. H. swART .REFRIGERATING APFARATU S Original Filed March 10, 1957 v iINVENTOR. Rw/zardff Qua/f2 n cy @l ATTORN 5.-

Patented Nov. 5,

UNITED sures 2,220,831: asrarcnnarmenrmnarns The invention'relates to refrigerating apparatus and has reference moreparticularly to improvements in an expansionvalvefor eillcientlyand uniformly distributing liquid refrigerant to 6 a plurality of evaporator passages arranged in parallel and joining .with a-cormnon suction v header.

An object of the invention is to provide an improved expansion valve which will uniformly Q distribute the liquid refrigerant by means of a novel distributor head having connection with a number of capillary tubes by which the liquid refrigerant is distributed to a plurality of evaporator passages. The tubes restrict the flow of the refrigerant to the evaporator passages, thereby maintaining a sufficiently high pressure to prevent evaporation of the liquid refrigerant in said header.

The uniformity of refrigerant distribution 30 from the various capillary tubes of the distributor head can be still further improved by precooling the liquid refrigerant admitted to the header. This is accomplished by providing a heat interchanger between the liquid refrigerant 25 supply and the suction line by which heat will be removed from the liquid refrigerant by the cool refrigerant gas being conducted to the compressor, as more particularly shown and described in the patent of Fred R. Erbach No..

cooled liquid in the distributor head a wide range of pressure is possible under varying operating conditions without interfering with the uniformity of refrigerant distribution.

35 Another object of the present invention resides in the provision of a novel distributor head for expansion valves which will impart a whirling motion to the liquid refrigerant to thereby more uniformly feed the liquid refrigerant to the pres- 40 sure regulating tubes connecting with said head.

With these and various other objects in view, the invention may consist of certain novel fea tures of construction and operation as will be more fully described and particularly pointed out 45 in the specification, drawing and claims appended hereto.

In the drawing which illustrates an embodiment of the invention and wherein like reference characters are used to designate like parts 50 Figure 1 is a longitudinal sectional view showing the improved distributor h'ead applied to a conventional expansion valve; and

Figure 2 is an elevational view of the distributor head of the invention. I

88 Referring to the drawing, the expansion valve PATENT, o-Fncsjdesignated in its entirety-by numeral is supplied with liquid refrigerant bythe tube H having connection with the body portion ll of the valve... A conical valve member I4 is formed on one end of the rod I! which has threaded con- 5 nection at'its other end with aspherical member .18. One side of said spherical member is in con- .tact with a part I! fixed to the underside of the pressure responsive diaphragm I8. The diaphragm is biased toward the right, Figure 1, in

a valve opening direction by pressure produced by a thermostat bulb 28, which pressure is communicated through the capillary tube 2| to the space on the left hand side of said diaphragm. The thermostatic bulb is adapted to be clamped in direct contact with the suction outlet of the refrigerating apparatus and thus the average discharge temperature of the refrigerant gas leaving the evaporators influences the thermostatic fiuid in said bulb to produce corresponding variations in pressure on the left hand side of the diaphragm. Under certain conditions of operation the pressure will be suilicient to force the valve member M in a direction toward the left, thereby opening the valve and admitting liquidrefrigerant to the header portion of the valve, which will be presently described.

The spherical member I6 is also in contact with a member 22 providing a spring seat for the coil spring 23 located Within chamber 24 so and encircling the valve rod l5. As a result of the tension exerted by the coil spring 23 the diaphragm I8 is biased toward the left in a valve closing direction. The member 25 is formed with a pinion 38 at its lower end which meshes with a somewhat larger pinion 39 integral with a threaded stem 40. Theseat 4] for the right hand end of the coil spring 23 has threaded con-' nection with said stem and therefore by rotating the stem, which is efiected by rotating member 0 25, the position of the seat can be varied. Thus the tension of said spring can be adjusted by member 25, having a slot 26 in its projecting end for receiving any suitable tool by which the member can be rotated. The chamber 24 is in 4 communication with the underside of the diaphragm I8 and said chamber is also connected by means of the nipple 21 with the tube 28. The other end of said tube is adapted to be connected to the suction header (not shown) of the refrigerating apparatus. Accordingly, the space on the underside of the diaphragm I8 is equalized with the pressurevof the evaporated refrigerant gas flowing through the suction header and which pressure will oppose that of the thermois portion 30.

static expansion bulb to cause ,closing of the valve.

The liquid refrigerant from the supply tube ll after flowing through the valved opening controlled by member i4 is admitted to the header portion 30 of the said expansion valve. A distributor head designated in its entirety by numeral 3i, Figure 2, is located within said portion. The liquid refrigerant first passes through the screen 32 and is then delivered by a plurality of openings 33 to a chamber 34 formed by said distributor head and the cylindrical walls of the The base of said chamber is provided with a plurality of outlet orifices 35 Which, as shown in Figure 1, have connection with pressure regulating tubes 36, respctively, each tube leading to and having connection with a cooling coil 31 comprising an independent evaporator which, however, joins with a suction header common to all said cooling coils.

In accordance with the invention the openings 33 in the distributor head extend in a diagonal downward direction so that the liquid refrigerant in passing through said openings is given a whirling motion. All the openings have substantially the same degree of slope and which has a direction to impart a whirling or rotating motion to -the liquid discharging therefrom. This has the result of more uniformly distributing the refrigerant to the outlet orifices 35 and as said orifices have the same level equal quantities of liquid refrigerant will be delivered to the capillary tubes 36.

In operation of the thermostatic expansion valve above described it may be assumed that at the start of the refrigerating cycle the evaporator coils 31 will be comparatively warm and the suction gas will therefore be superheated. Since the pressure produced by the thermostatic bulb 20 is proportional to its temperature, the pressure on the left side of the diaphragm i8 will therefore be greater than the suction pressure within chamber 24 plus the tension exerted by the coil spring 23. This will result in Opening of valve l4. Eventually the temperature within the evaporating coils 31 will drop and as this cooling continues the thermostatic bulb 20 will be effected, causing a drop in the pressure on the left of the diaphragm so that the tendency of the valve member i4 is to close. This action of the valve member is also augmented by the rise in the suction pressure within chamber 24 which is further aided by the tension of the coil spring 23. The difference in the pressures imposed on the diaphragm is a function of the heat of the refrigerant leaving the series of evaporating coils 31. As the tension of the coil spring 23 aids the closing of the valve the member 25 for varying the tension of said coil spring is known as the external superheat adjustment.

The expansion valve, provided with the header portion in accordance with the invention, is disposed so as to locate the distributor head 3| in a horizontal plane wherebythe outlet orifices are on an even level and an equal quantity of liquid refrigerant should be supplied thereto.

' However, it is also necessary to maintain the liquid refrigerant evenly distributed over the symmetrically arranged outlet orifices and this function is accomplished by. the diagonal openings 33. The liquidrefrigerant supplied to the present valve will also have been precooled in a a manner as previously described and therefore a sufliciently high pressure can be maintained within the expansion valve to prevent evaporation of the refrigerant.

This application is a divisional of an original application Serial No. 130,028 which issued as Patent No. 2,158,793 May 16, 1939.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawing, as various other forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. Means for uniformly distributing liquid refrigerant to a plurality of evaporator elements comprising an expansion valve, said valve having a header portion adapted to receive the liquid refrigerant from said valve, a. distributor head in said header portion having a plurality of outlet orifices symmetrically arranged in the base thereof, means extending from said base and connecting each orifice with one of said evaporator elements whereby liquid refrigerant is delivered thereto, and said distributor head having openings located above the outlet orifices arranged to impart a whirling motion to the liquid refrigerant stream flowing therethrough to uniformly distribute the refrigerant to said outlet orifices.

2. Means for uniformly distributing liquid refrigerant'to a plurality of evaporator elements comprising an expansion valve, said valve having a header portion adapted to receive the liquid refrigerant from said valve, a distributor head in said header portion having a pluralityof outlet orifices symmetrically arranged in the base thereof, capillary tubes extending from said base and connecting each orifice with one of said evaporator elements whereby liquid refrigerant is delivered thereto, and said distributor head having openings located above the outlet orifices arranged to impart a whirling motion to the liquid refrigerant stream flowing therthrough to uniformly distribute the refrigerant to said outlet orifices.

' RICHARD H. SWART. 

